Siphon jet toilet

ABSTRACT

A siphon jet toilet for supplying flush water in a storage tank by using the head pressure thereof is disclosed. The siphon jet toilet has a toilet main unit furnished with a bowl portion, a rim water spout, a drain trap passage for expelling waste using siphon action, a jet water spout opening formed at a position opposite the inlet of the drain trap passage, a rim water channel for supplying flush water to the rim water spout opening, and a jet water channel for supplying flush water to the jet water channel. The jet water channel includes a plurality of branched water conduits, a merging portion for causing flush water from the plurality of branched water conduits to merge and swirl toward the jet water spout opening and a flow aligner for aligning the flow of flush water merged in the merging portion. The merging portion including an outer wall portion formed in essentially a straight line so that flush waters in the outer region of the swirl collide head-on and an inner wall portion on which a bent portion is formed so that flush water in the inner region of the swirl flows smoothly toward the jet water spout opening.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a siphon jet toilet, and in particular to a siphon jet toilet for supplying flush water in a storage tank by using the head pressure of flush water.

2. Description of the Related Art

Siphon jet toilets are conventionally known in which flush water is supplied to a jet water spout opening formed on the bowl portion of the main body of a toilet using the head pressure of flush water stored in a storage tank, and waste is expelled to the outside using the siphon action of a drain trap passage. In conventional siphon jet toilets, as shown in FIG. 10, flush water from a storage tank (not shown) is supplied to a jet water spout opening 4 via a jet water channel 2 formed on a bowl portion 1, therefore the jet water channel 2 has a U shape when seen in planar view.

However, when the jet water channel 2 has a U shape, flush water supplied from the jet water channel 2 takes on a swirl flow D as shown in FIG. 11, and flush water spouted from the jet water spout opening 4 (swirl flow D) takes on a flow with a biased flow rate distribution (also called curve momentum), whereby outer flow rate is fast and inner flow rate is slow.

This type of biasing of the flow rate distribution of flush water spouted from the jet water spout opening 4 results in a delay in filling the drain trap passage, which in turn delays the start of the siphon action.

To correct this biasing of the flow rate distribution, the siphon jet toilet in Japanese Utility Model Publication No. 1-44616 is known, whereby as shown in FIG. 12, a jet water channel 2 is divided into two branched jet water channels 2 a and 2 b going from the upstream side to the downstream side, and these branched jet water channels 2 a and 2 b are arranged so that their downstream side faces the jet water spout opening 4. In the siphon jet toilet of Japanese Utility Model Publication No. 1-44616, flush water from the two branched jet water channels 2 a and 2 b merges in a merging portion 6 white swirling, therefore the biasing (curve momentum) of the flush water flow rate distribution in the respective branched jet water channels 2 a and 2 b is canceled; since flow volume is doubled by the simultaneous merging, the pressure of flush water in the merging portion 6 rises and flush water is spouted toward the jet water spout opening 4, which is the only outlet.

A known means to correct this biasing of the flow rate distribution is the siphon jet toilet disclosed in U.S. Pat. No. 7,111,333, whereby as shown in FIG. 13, two branched jet water channels 2 a and 2 b are provided, as with Japanese Utility Model Publication No. 1-44616, and the downstream side of these two branched jet water channels 2 a and 2 b is bent to have a curved portion 8, and the merging portion 6 is formed to contain a somewhat large space.

Here, in a siphon jet toilet for supplying flush water using the head pressure of flush water in a storage tank, flush water is supplied from a storage tank upon flushing and the jet water channel fills with water, such that the head pressure of flush water in the storage tank (the water pressure head) impinges on the accumulated water in the bowl portion.

Also, the siphon jet toilet expels waste outside using the waste pulling action of the siphon and the waste pushing action of the water pressure head.

Therefore in the siphon jet toilet, the higher the height (H) from the accumulated water in the bowl portion to the water level of the flush water in the storage tank at the instant the jet water channel is filled with water, the greater the water pressure head, and hence the higher the cleansing capability.

In this regard, in the toilet pre-flush state (the initial state), the inside of the jet water channel is open to the atmosphere, resulting in a disconnection between the flush water in the storage tank and the accumulated water in the bowl portion. Therefore after commencing flushing of the toilet, it is necessary when supplying the flush water in the storage tank to the bowl portion to expel air present in the jet water channel. There is a risk that the presence of air in the jet water channel will buffer the water head pressure in the storage tank and thereby reduce the flow rate of flush water from the jet water spout opening. A reduced flush water flow rate delays the start of the siphon action, so that flush water is wastefully consumed and the need for water conservation cannot be met.

Considering such properties of a siphon jet toilet, in the above-described Japanese Utility Model Publication No. 1-44616 siphon jet toilet the two flush waters collide head-on over essentially the entire area upon merging, so that the air in the branched jet water channels 2 a and 2 b can be expelled in a short period of time, on that point is effective, but there is a large pressure loss due to the full area head-on collision, such that positional energy is lost and the flow rate of flush water spouted from the jet water spout opening 4 is reduced. When the flow rate of the flush water drops, the start of the siphon action is delayed, that portion of flush water is wastefully consumed, and the toilet cannot fulfill the need for water conservation.

Moreover, in the above-described siphon jet toilet in U.S. Pat. No. 7,111,333, there is no head-on collision across essentially the entire area of the two flush waters upon merging as there is in Japanese Utility Model Publication No. 1-44616, and the merging portion is a somewhat larger space, so pressure loss is thought to be ameliorated, but appropriate pressure loss capable of expelling air in the jet water channel in a short time cannot be established with this toilet.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a siphon jet toilet capable of conserving the volume of flush water used for flushing the toilet.

Another object of the is to provide a siphon jet toilet capable of securing the same or better flushing functionality as conventional products using a smaller volume of flush water than those conventional products.

In order to achieve the object above, the present invention provide a siphon jet toilet for supplying flush water in a storage tank by using the head pressure thereof, comprising a toilet main unit furnished with a bowl portion having a waste receiving surface, a rim water spout formed on the top edge of the bowl portion, a drain trap passage provided at the bottom portion of the bowl portion for expelling waste using siphon action, a jet water spout opening formed at a position opposite the inlet of the drain trap passage on the bowl portion, and a rim water channel for supplying the flush water in the storage tank to the rim water spout opening, and a jet water channel for supplying the flush water in the storage tank to the jet water channel, said jet water channel including a plurality of branched water conduits branched from the upstream side toward the downstream side thereof, a merging portion for causing the flush waters from the plurality of branched water conduits to merge and swirl toward the jet water spout opening and a flow aligner for aligning the flow of the flush water merged in the merging portion, said merging portion including an outer wall portion formed in essentially a straight line so that the flush waters in the outer region of the swirl collide head-on and an inner wall portion on which a bent portion is formed so that flush water in the inner region of the swirl flows smoothly toward the jet water spout opening.

In the present invention thus constituted, the air does exist in the jet water channel in the initial state when using the toilet, but when flushing commences, flush water in the storage tank is supplied to the jet water channel. At this point the outer wall portion of the merging portion is formed in essentially a straight line, therefore only the outer region flush waters swirling from the jet water channel collide head-on; this causes the pressure inside the jet water channel to rise instantaneously, such that air remaining in the jet water channel is expelled from above, and the jet water channel is filled with water in a short time. As a result, the jet water channel in the present invention is filled with water in a short time, therefore the large level difference H between the flush water in the storage tank and the accumulated water in the bowl portion (the water pressure head) acts so that a large expelling action (expulsion force) on the waste can be obtained and, moreover, the siphon action can be induced at an early point.

Because, in the present invention, the merging portion has an inner wall portion in which a bent portion is formed, swirling inner region flush water flows smoothly toward the jet water spout opening.

In the present invention only the swirling outer region flush waters from the jet water channel are caused to collide head-on, rather than causing all of the flush waters from the jet water channel to collide head-on, therefore inner region flush water flows smoothly, such that energy losses can be reduced to a minimum.

In a preferred embodiment of the present invention, the bent portion of the inner wall portion in the merging portion has curvature radius in a range of 15 mm to 30 mm in planar view.

In the embodiment of the present invention thus constituted, the swirling inner region flush water in the merging portion can be flowed smoothly toward the jet water spout opening without colliding, such that energy losses in the merging portion can be reduced to a minimum.

In a preferred embodiment of the present invention, the flow aligner has a predetermined length in the horizontal direction, and is formed to extend in essentially the horizontal direction toward the drain trap passage.

In the embodiment of the present invention thus constituted, the flow aligner permits the flow of flush water to be aligned even in the height direction. As a result, the siphon action can be induced at an early point, which in turn enables flushing with a small volume of flush water.

In a preferred embodiment of the present invention, the volume of flush water stored in the storage tank is in a range of 2.5 liters to 6.5 liters.

In the embodiment of the present invention thus constituted, a toilet can be flushed with a low 2.5 liter to 6.5 liter volume of water.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a front elevation cross sectional view showing a siphon jet toilet according to an embodiment of the present invention;

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a cross sectional view along a line III-III in FIG. 1;

FIG. 4 is an expanded plan view showing the jet water channel, the merging portion, and the flow aligner in the siphon jet toilet of the embodiment of the present embodiment;

FIG. 5 is an enlarged partial plan view of FIG. 4;

FIG. 6 is an enlarged partial plan view of FIG. 4;

FIG. 7 is an enlarged partial front elevation view of FIG. 1;

FIG. 8 is a partial cross sectional view showing the initial state of a siphon jet toilet in the embodiment of the present invention;

FIG. 9 is a partial cross sectional view showing the commence flush state of the siphon jet toilet in the embodiment of the present invention;

FIG. 10 is a plan view showing a conventional siphon jet toilet;

FIG. 11 is an enlarged plan view showing the biasing (curve momentum) of flow rates in a swirling flow of flush water in the conventional siphon jet toilet;

FIG. 12 is a plan view of a conventional siphon jet toilet; and

FIG. 13 is a partial enlarged plan view of the conventional siphon jet toilet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Next, referring to the attached drawings, a siphon jet toilet according to an embodiment of the present invention will be discussed. First, referring to FIGS. 1 through 3, the basic structure of a siphon jet toilet according to the embodiment of the present invention is discussed. FIG. 1 is a front elevation cross sectional view showing a siphon jet toilet according to the embodiment of the present invention; FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a cross sectional view along line III-III in FIG. 1.

As shown in FIGS. 1 through 3, the siphon jet toilet 10 according to the embodiment comprises a toilet main unit 12 and a storage tank 14 for storing flush water, disposed at the upper rear portion of the toilet main unit 12. The storage tank 14 stores 2.5 liters to 6.5 liters of flush water.

The toilet main unit 12 comprises a bowl portion 16 at the front portion thereof; on the bowl portion 16 are formed a bowl-shaped waste-receiving surface 18 and a rim 20, which is the top edge portion thereof. An expelling opening 22 for expelling waste is formed at the bottom portion of the bowl portion 16.

Rim spout openings 24 (24 a, 24 b) for spouting flush water are formed at two locations on the rim 20 which forms the top edge portion of the bowl portion 16; a jet water spout opening 26 is formed at the lower front side of the bowl portion 16 toward the expelling opening 22.

Additionally, a drain trap passage 28 is formed at the at the lower rear side of the bowl portion 16 for expelling waste by siphon action.

The jet water spout opening 26 is here formed in a position facing the drain trap passage 28 inlet 28 a via the expelling opening 22.

Additionally, a water supply chamber 30 to which flush water is supplied from the storage tank 14 is formed at the upper rear portion of the toilet main unit 12; on this water supply chamber 30 and connected thereto are provided a rim raceway 32 for guiding flush water to the above-described rim spout openings 24, and a jet water channel 34 for guiding the flush water to the jet water spout opening 26.

Going from the upstream side to the downstream side, as seen from the front of the toilet main unit 12, the jet water channel 34 is split into two branches: a first jet water channel 34 a on the right, and a second jet water channel 34 b on the left.

A merging portion 36 for merging the flush water from the jet water channels 34 a and 34 b is formed on the downstream side of the 0[right side] first jet water channel 34 a and the left side second jet water channel 34 b, and a flow aligner 38 for aligning the flow of the merged flush water is formed at the downstream side of the merging portion 36; the downstream end of the flow aligner 38 is the jet water spout opening 26 discussed above.

Next, referring to FIGS. 4 through 7, we discuss the jet water channels 34 a and 34 b, the merging portion 36, and the flow aligner 38 in the siphon jet toilet of the present embodiment. FIG. 4 is an expanded plan view showing the jet water channel, the merging portion, and the flow aligner in the siphon jet toilet of the present embodiment; FIGS. 5 and 6 are expanded partial plan views of FIG. 4, and FIG. 7 is an expanded partial front elevation of FIG. 1.

First, as shown in FIGS. 4 through 6, flush waters A (see FIG. 4) from the jet water channels 34 a and 34 b merges in a swirling state in the merging portion 36. Because the flush water A is here a swirling current, the flow rate of outer region flush water B in the merging portion 36 (see FIG. 5) is fast, whereas the flow rate of inner region flush water C in the merging portion 36 (see FIG. 6) is relatively slow.

In the embodiment, therefore, as shown in FIG. 5, the merging portion 36 is furnished with a outer wall portion 40 positioned on the far side of the jet water spout opening 26; this outer wall portion 40 is formed in essentially a straight line.

A more detailed discussion appears below, but in the embodiment the outer region flush waters B of the flush waters A from the left and right jet water channels 34 a and 34 b collide head-on.

Next, as shown in FIG. 6, in the embodiment the merging portion 36 is furnished with an inner wall portion 42 positioned on the near side of the jet water spout opening 26; this inner wall portion 42 is formed as a bent portion having a curvature radius R in planar view in such a way that the inner region flush waters C of the flush waters A from the jet water channels 34 a and 34 b flow smoothly toward the jet water spout opening 26. In the embodiment the curvature radius R is preferably in a range of 15 mm to 30 mm.

Additionally, as shown in FIG. 7, the flow aligner 38 for aligning the flow of merged flush water is formed to extend in a essentially straight line in the horizontal direction toward the drain trap passage 28 entry opening 28 a. The flow aligner 38 preferably has a length of 10 mm or greater, and more preferably a length of 10 mm to 30 mm.

Next the operation of the siphon jet toilet in the above-described embodiment of the present invention. First, in the initial state (prior to use of the toilet), the siphon jet toilet 10 of the embodiment is in a state whereby, as shown in FIG. 8, the water supply chamber 30 and the upper portion within the jet water channel 34 are open to the atmosphere and air is present, and flush water in the storage tank 14 is disconnected from accumulated water in the bowl portion 16.

Starting from this initial state, when flushing commences, as shown in FIG. 9, the water supply chamber 30 and the jet water channel 34 fill with flush water from the storage tank 14. Next, a water pressure head expressed by the level difference H between flush water in the storage tank 14 and the accumulated water in the bowl portion 16 acts on the accumulated water in the bowl portion 16. Thereafter flush water from the jet water channel 34 is spouted from the jet water spout opening 26 via the merging portion 36 and the flow aligner 38 to the drain trap passage 28. The drain trap passage 28 fills with water, and waste is expelled to the outside by the waste-pulling action of the siphon and the waste pushing action of the water pressure head itself. Therefore the higher the level difference height H between flush water in the storage tank 14 and the accumulated water in the bowl portion 16 at the instant the jet water channel is filled with water, the greater the water pressure head, and hence the higher the cleansing capability.

Next, as shown in FIG. 5, the outer wall portion 40 positioned on the far side of the merging portion 36 jet water spout opening 26 is formed in essentially a straight line, therefore the outer region flush waters B of the flush waters A from the left and right jet water channels 34 a and 34 b collide head-on.

The head-on collision of the flush waters B from the left and right jet water channels 34 a and 34 b causes the pressure in the jet water channels 34 a and 34 b to rise instantaneously, such that the air accumulated inside the jet water channels 34 a and 34 b in the initial state shown in FIG. 8 is pushed out by the rim water channel 32, which results in the jet water channels 34 a and 34 b filling with water in a short time.

Thus not all flush waters from the jet water channels 34 a and 34 b is caused to collide head-on in the embodiment as it is in Japanese Utility Model Publication No. 1-44616 siphon jet toilet; instead only a portion of the outer region of the swirling flush water is caused to collide head-on, therefore compared to the toilet of Japanese Utility Model Publication No. 1-44616, energy loss can be reduced to a minimum when the water pressure head of the flush water in the storage tank 14 is caused to act on the accumulated water in the bowl portion 16.

Next, as shown in FIG. 6, in the embodiment the inner wall portion 42 positioned on the near side of the merging portion 36 jet water spout opening 26 is formed with a curvature radius R, therefore the inner region flush waters C of the flush waters A from the jet water channels 34 a and 34 b flows smoothly toward the jet water spout opening 26.

Thus not all flush water from the jet water channels 34 a and 34 b is caused to collide head-on in the embodiment as it is in the Japanese Utility Model Publication No. 1-44616 siphon jet toilet; instead only flush water B in the outer region, which is a portion of the swirling flush water, is caused to collide head-on, and flush water C in the inner region flows smoothly without colliding, so that compared to the toilet of Japanese Utility Model Publication No. 1-44616, energy losses can be reduced to a minimum when the water pressure head of the flush water in the storage tank 14 is caused to act on the accumulated water in the bowl portion 16.

Also, in the present embodiment the flush water from the two jet water channels 34 a and 34 b of the jet water channel 34 is caused to merge in the merging portion 36, therefore the biases (curve momentums) of flow rate distribution in the swirling flow present in the lateral direction seen in planar view cancel one another out, and as a result the flush water spouted from the jet water spout opening 26 becomes a perfectly straight water flow relative to the drain trap passage 28. That is, the rate distribution in the lateral direction becomes uniform, and the energy held by the flush water in the storage tank 14 (the water pressure head) can be efficiently used to expel waste, which further enables siphoning to be started at an early point.

Additionally, in the embodiment as shown in FIG. 7, a flow aligner 38 is erected at the down-flow portion of the merging portion 36 in order to align the flow of merged flush water, therefore flush water spouted from the jet water spout opening 26 becomes a perfectly straight water flow relative to the drain trap passage 28. That is, the rate distribution becomes uniform in the vertical direction as well, and to that extent the energy held by the flush water in the storage tank 14 (the water pressure head) can be efficiently used to expel waste, which further enables siphoning to be started at an early point.

Although the present invention has been explained with reference to a specific, preferred embodiment, one of ordinary skill in the art will recognize that modifications and improvements can be made while remaining within the scope and spirit of the present invention. The scope of the present invention is determined solely by the appended claims. 

1. A siphon jet toilet for supplying flush water in a storage tank by using the head pressure thereof, comprising: a toilet main unit furnished with a bowl portion having a waste receiving surface; a rim water spout formed on the top edge of the bowl portion; a drain trap passage provided at the bottom portion of the bowl portion for expelling waste using siphon action; a jet water spout opening formed at a position opposite the inlet of the drain trap passage on the bowl portion; a rim water channel for supplying the flush water in the storage tank to the rim water spout opening; and a jet water channel for supplying the flush water in the storage tank to the jet water channel; said jet water channel including a plurality of branched water conduits branched from the upstream side toward the downstream side thereof, a merging portion for causing the flush waters from the plurality of branched water conduits to merge and swirl toward the jet water spout opening and a flow aligner for aligning the flow of the flush water merged in the merging portion; said merging portion including an outer wall portion formed in essentially a straight line so that the flush waters in the outer region of the swirl collide head-on and an inner wall portion on which a bent portion is formed so that flush water in the inner region of the swirl flows smoothly toward the jet water spout opening.
 2. The siphon jet toilet according to claim 1, wherein the curved portion of the inner wall portion on the merging portion has a curvature radius in the range of 15 mm-30 mm as seen in planar view.
 3. The siphon jet toilet according to claim 1, wherein the flow aligner has a predetermined length in the horizontal direction and is formed to extend in essentially the horizontal direction toward the drain trap passage.
 4. The siphon jet toilet according to claim 2, wherein the flow aligner has a predetermined length in the horizontal direction and is formed to extend in essentially the horizontal direction toward the drain trap passage.
 5. The siphon jet toilet according to claim 1, wherein the volume of flush water stored in the storage tank is in the range of 2.5 liters to 6.5 liters.
 6. The siphon jet toilet according to claim 2, wherein the volume of flush water stored in the storage tank is in the range of 2.5 liters to 6.5 liters.
 7. The siphon jet toilet according to claim 3, wherein the volume of flush water stored in the storage tank is in the range of 2.5 liters to 6.5 liters.
 8. The siphon jet toilet according to claim 4, wherein the volume of flush water stored in the storage tank is in the range of 2.5 liters to 6.5 liters. 